Number of edges in the n-th Mycielski graph. This sequence of graphs is formed, starting from the empty graph, by repeatedly applying a construction of Mycielski for generating triangle-free graphs with arbitrarily large chromatic number.

The first few graphs in the sequence of Mycielski graphs are the null graph, K1, K2, C5 and the Graezsch graph with 11 vertices and 20 edges. Thus the first entries in this sequence are 0, 0, 1, 5 and 20.